How and Why Steel Quality Control Should Be Conducted

Steel is one of the world’s most important engineering and construction materials. The metal is manufactured primarily from iron with the addition of carbon and a number of other elements.

It’s durable while a low amount of energy is used to produce lightweight steel and it can also be designed into various forms. Household products such as fridges, TVs, ovens and sinks can be made from steel and cutlery is made from stainless steel. It’s also a metal used for producing industrial goods such as farm vehicles and machines.

Why Quality Control for Steel is Important

Quality steel is a must in order to  avoid steel structure fatigue or failure. Problems that can arise during manufacturing could result in weakness, particularly when the surface is folded or moulded.

Inspection is an integral part of quality control; its purpose is to check that the requirements of the specification are being complied with. Checking the processes, procedures and materials required for the manufacturing of steel structure is vital as durability can be significantly reduced if not fully complied with.

A third-party inspection company is an essential step when inspecting the quality of steel. If issues are not rectified immediately it can reduce the expected timescale  to when the first maintenance of the material will be needed. To specify the various physical and mechanical properties of the finished product, various tests, both destructive and non-destructive, need to be performed.

How Can You Tell the Quality of Steel?

A range of tests exist to test the strength and durability of steel. The following are some of the ways quality control is carried out on the material.

Metallurgical

Metallurgical testing is used to determine the quality of steel by analysing the microstructure of a sample under a microscope. A section of the sample is firstly polished and then examined and different characteristics are produced through mixing the steel with other substances.

Hardness

Hardness is not a vital property of a material, but it is related to the elasticity and plasticity. The hardness value test helps to compare between the materials or treatments. These tests are usually performed by impressing a test specimen, which is resting on a rigid platform under a static load.

Hardenability

Hardenability determines the depth and distribution of hardness induced by quenching. Also known as the Jominy Test. A long sample is heated uniformly to the correct temperature before the sample is removed from the furnace and placed on a fixture where water contacts the bottom face of the sample. After 10 minutes, the sample is removed and the results should show a curve of hardness versus the distance from the quenched end.

Tension

A tension test runs at a constant load and temperature. The strength of the material is tested to ensure its ability to withstand external forces without breaking. By pulling on something, you can quickly determine how the material will react to forces being applied in tension.

Ductility

The ductility of a material is indicated by the amount of deformation that’s possible until it breaks. This can be determined by measuring the area of a sample that has been tested to failure.

Compression

Compression tests are performed on small cylinders, blocks or strips to determine the ability of the material and whether it can undergo large plastic deformations and its limits. Samples are placed between pressure plates and compressed.

Fatigue

This test is used to determine the behavior of the materials when subjected to reparations of fluctuating loads. Used to simulate stress conditions that’ll be developed in materials under normal service conditions. The fatigue limit is shown by counting the number of stress cycles applied in one direction and then another, until the steel breaks.

Impact

Impact tests are used to indicate the behavior of the materials when subjected to high rates of loading, usually bending, tension or torsion. A swinging pendulum of a fixed weight raised to a standard height is used to strike the sample and the weight of the pendulum times the difference in heights helps to indicate the amount of energy absorbed by the specimen.

Wear

Wear resistance is a complex test and usually applied to specific equipment designed to simulate actual service conditions. Various types of environmental testing are carried out to witness how the material reacts to actual conditions.

Corrosion

Corrosion tests involve the destruction of a material by chemical, electrochemical or metallurgical interaction between the environment and material. Various types of environmental exposure tastings are done to simulate actual use conditions.

Creep

Creep tests are used to determine the continuing change in the deformation of a material at elevated temperatures when stressed below the yield strength. A creep test is a tension test run at a constant load and temperature.

Machinability

Machinability is the ease with which metal may be machined and many factors are considered in arriving at machinability ratings which are expressed as a percentage in compassion with AISI 1112 steel, which is rated at 100%.

Radiography

Radiography of metals involves the use of x-rays and the short-wavelength electromagnetic rays that are capable of passing  through large thicknesses of metal and are typically used to test casting and welded joints for shrinkage voids.

Magnetic Particle

Magnetic particle inspection is a method of detecting cracks, tears, seams, and inclusions in steel and iron. This method will detect any discontinuities just below the surface that are hard to spot with the naked eye.

Ultrasonic

Ultrasonic testing utilizes sound waves above the audible range and this non-destructive test employs electronically produced high-frequency sound waves to penetrate metals and other materials. It is used to detect and locate such defects as shrinkage voids, internal cracks, porosity and large non-metallic inclusions.

Eddy

Eddy inspection is used to inspect electrically conducting materials for defects and variations in composition. Eddy testing involves placing a varying magnetic field near an electrically conducting sample. Properties such as hardness, alloy composition, chemical purity and heat treat conditions can influence the magnetic field and may be measured through the use of eddy current tests.

What Kind of Steel Products Require Quality Control?

Steel comes in many different forms and the third-party inspection company, HQTS offers quality control tests for many different products including; bars, chains, containers, ingots, metallic plates, sheets, strips and coils, nets, fences, section bars, tubes and wires.

Combine this with HQTS’ quality standards and services and you have a powerful, profitable and productive commercial proposition. HQTS will help ensure your packaging is up to the task and that your goods are effectively secure and protected throughout the transport process.

About HQTS

Headquartered in Asia and with multiple service locations around the world, HQTS provides supply chain quality solutions to a wide range of global companies. Quality expectations and the range of safety requirements you must achieve are becoming increasingly complex. When your product fails to meet quality expectations within the market, the result can be loss of good will, product and revenues, customers, delayed shipments, wasted materials and the potential risk of product recalls. HQTS has the right systems, processes and procedures to help you meet requirements and deliver quality products in a timely manner.

Related articles

Pre-Shipment Inspection of Construction Machinery

Keeping Track of Your Automotive Quality Control

Sources

https://science.jrank.org/pages/6485/Steel-Quality-control.html#:~:text=To%20specify%20the%20various%20physical,destructive%20and%20nondestructive%2C%20are%20performed.&text=Metallurgical%20testing%20is%20used%20to,a%20sample%20under%20a%20microscope

http://www.valbruna-stainless-steel.com/quality/controls

https://civiltoday.com/civil-engineering-materials/steel/214-uses-of-steels



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